Driving mechanism



1942- s. M. COFFMAN DRIVING MECHANISM 2 Sheets-Sheet 1 Filed Dec. 2, 1940 Ii? Samuel/H400 Jan. 6, 1942. 1M. COFFMAN 2,268,802

- DRIVING MECHANISM Filed Dec. 2, .1940 :2 Sheets-Sheet 2 Patented Jan. 6, 1942 DRIVING MECHANISM Samuel Coffnian, Kansas City, Mo. Application December- 2, 1940, Serial No. 368,191 6 Claims. mo 74-396) This invention relates to a driving mechanism whereby wrenches, screw drivers, drills or other .rotatable devices may be operated by motor power instead of by slow and laborious hand power.

The driving mechanism is portable so that it may be carried around like a hand tool and is equipped to be coupled to differentkinds of tools for operating both. accessible and comparatively inaccessible parts, such, for instance, as the nuts or cap screws employedin securing the cylinders ofv airplane engines in place.

The device is adapted to be drivenbyan electric motor through the medium of a flexible shaft, and embodies a handle, worm gearing associated with said handle,'and controlling means operably mounted on the handle and whereby the worm gearing may beinstantlythrownin .or

out of mesh.

Other objects will hereinafter appear and in order that the inventon may be fully understood, reference will now be had to theaccompanying drawings, in which:

Fig. 1 is a perspective .view of the driving mechanism coupled .to a wrench, and means for operating said driving mechanism.

Fig. 2 is a side elevation of the driving mechanism coupled tov the wrench.

Fig. 3 is a sectional view of the driving mechanism on line 3-3 of Fig. 2, with the wrench removed and part of the operating means added. Fig. 4-is a plan view of the wrench.

Fig. 5 is a plan view of the wrench with its face plate removed to show a train of gearing. used in driving the rotatable nut or cap screw engaging member of the wrench.

Fig. 6 is a reduced side elevation of the wrench with manual means for driving the trainof gea'r-. ing that drives the rotatable member.

Fig. 7 is a fragmentary side view of {a portion of a radial engine with the wrench applied.

to one of the cap screws.

movably held in place with suitable means such, for instance, as screws I2."

Arrangedwithin the chamber 4 are two inter-- meshing gear wheels I4 and-I6,- and a rotatable '5 member I8 having peripheralgear teeth-20 -intermeshing with the teethof the gear wheel I 6" which is journaled upon a stubshaft-22 fixed-to the .back wall of the chamber and extending through an aperture 23in thefa'ce plate l0; As best shown by Figs. 2 and '5- the. rotatable member I8 has a hub 24 mounted in the apertures Band- 8, and a transverse opening 26 of polygonal form to fitover a nut or the head of-a cap screw. In

the present instance'the opening 26 is of-hexag I .tonal form, but openings of other shapes may be used.

In order that the wrench may be used on nuts and cap screws of various sizes without-providing a number of interchangeable. rotatable membets [8, any desired number of interchangeable I socke'mmember's 250i different sizes may be em- Fig. 8 is a horizontal section on line 8--8 of Fig. 7.

Fig. 9 is a detail of one of a number of different size socket members which may beused with the wrench.

Referring now more particularly to the wrench proper which is adapted to .be operated by the driving mechanism, 2 designates a member in the form of a handle provided with a longitudinal gear chamber 4 communicating with respective registering transverse apertures 6 and 8 in the back wall of the chamber and a face plate. In

covering the open'front of the chamber and reployed having polygonal shanks 21 adapted to fit in the. opening 26. i Eithermanual or the power driving mechanis may be employed for operating the wrench. The manual means may bein the form of a simple crank having a socketmember 28 adapted to pass through registering openings 28a, 28b, and 280 in the face plate 10,.the gear wheel I and the back of the gear chamber 4, respectively. The socket member 28 has notches 28d toiengage over a pin 29 fixed to the geariwheel. Hand extending across the opening 281). 1

.Referring now more particularly to the power driving mechanism, 30 designates a handle. consisting preferably of hard rubber having a tubular member 3| extending longitudinally therethrough and equipped with bearings 32 for ashaft 34 provided near its forward end with a thrust collar 36 and a worm gear 38. The shaft 34 is heldfrom backward movement by the "collar 3B which bears against the forward end of theadiacentf bearing '32, and held from forward movement by a thrust bearing .40 threaded in the forward end of the tubular member 3!.

Theworm gear 38 is adapted to intermesh with a worm wheel 42 located in a recess 44 in the en- 1 larged forward end of a controlling member 46 rockably mounted intermediate its ends upon an element 48 threaded at itsinner end in the tubu-. I

lar member 3| and provided at its outer end with a screw 50, the head 52 of which retains the member 46 in place. The worm wheel 42 is yieldably. held out of mesh with the'worm gear '381-"by arc'oil" spring 54 interposedbetween thchandle 30 and the inner end of a cavity 56 formed in the controlling member 46, which latter is preferably made in two parts so that the worm wheel 42 and a shaft 58, upon which the worm wheel is fixed, may be readily assembled with said controlling member, the two parts of which are removably secured together by suitable means such as screws 60.

Registering slots 62 and 64 are formed in the forward portion of the tubular member 3| and the controlling member 46, respectively, to permit the worm wheel 42 to engage the worm gear 38 when the controlling member 46 is manually pressed toward the handle 30 against the action of the spring 54. The side walls of the slot 62 overlap the side walls of the slot 64 to prevent the controlling member 46 from swinging laterally upon the element 48 and carrying the worm wheel 42 out of position for engagement with the worm gear 38.

The rear end of shaft 34 has a counterbore 66 for reception of the forward end of a flexible shaft 68 driven by suitable means, such as an electric motor 16. The shaft 68 drives the shaft 34 through a lug 12 adapted to enter a slot I4 in the rear portion of the shaft 34. is housed in a non-rotary fiexible tube l6 connected at one end to the stationary housing of the motor 18 by a coupling 18, and removably connected at its opposite end to the tubular member 3| with a coupling 80 provided with a latch 82 mounted on a pivot 84 and provided at its reduced forward end with a shoulder 86 for engagement with the rear wall of an annular groove 88 in the rear portion of the tubular member 3|. Spring means 90 is provided for normally holding the latch 82 in active position.

In practice, assuming that when the working parts are in the position disclosed by Figs. 1 and 2, the rotatabl member l8 of the wrench will Shaft 68 be driven clockwise to screw a nut upon a bolt,

it is apparent that the rotatable member I8 may be driven counterclockwise to unscrew the nut by disengaging the notched end 92 of shaft 58 from gear wheel [4, rotating the handle 38 axially one-half revolution to carry member 46 to the dotted line position Fig. 3, engaging the gear wheel l4 with the notched end 94 of the shaft 58, and engaging the worm wheel 42 with the worm gear 38. During the foregoing operations it will not be necessary to change the position of the wrench 2.

Fig. 1 shows the handle 30 arranged in parallel relation to the wrench 2, but, using shaft 58 as a pivotal point, the wrench may be swung at different angles to handl 38, if it will aid in reaching a somewhat inaccessible nut, or machine screw.

Figs. 7 and 8 show fragments of a radial engine A with the wrench applied to one of the cap nuts B that secures the cylinders to the crank case.

From the foregoing description taken in connection with the drawings, it is apparent that by driving the rotatable member I8 continuously inone direction to screw a nut, or cap screw into position, or continuously in a reverse direction to unscrew the nut, or cap screw that the work of applying or removing a large number of nuts, or cap screws may be greatly expedited and accomplished with less labor than is possible with the ordinary type of wrenches now in general use.

Although I have shown the driving mechanism applied to a wrench, it is to be understood that it may be employed to advantage for operating screw drivers, drills and other rotatable devices, and while I have shown a preferred form of my driving mechanism I reserve all rights to such other forms and modifications thereof as properly fall within the spirit and scope of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:

1. A driving mechanism comprising a handle, a shaft located in said handle, means for driving said shaft, a first gear fixed to said shaft, a second gear adapted to be driven by said first gear, a rotary member fixed to the second gear and adapted to drive a rotatable tool, and manually actuated controlling means in which the rotary member is journaled, said controlling means being operably mounted upon the handle and adapted to engage or disengage the second gear from the first gear.

2. A driving mechanism comprising a handle, a tubular member secured in said handle, a shaft journaled in said tubular member, means for driving said shaft, a first gear fixed to said shaft, a second gear adapted to be driven by said first gear, a rotary member fixed to the second gear and adapted to drive a rotatable tool, and manually actuated controlling means in which the rotary member is journaled, said controlling means being operably mounted upon the handle and adapted to engage or disengage the second gear from the first gear.

3. A driving mechanism comprising a handle, a shaft located in said handle, means for driving said shaft, a first gear fixed to said shaft, a second gear adapted to be driven by said first gear, means fixed to the second gear and adapted to drive a rotatable tool, manually actuated controlling means in which the second gear is lo- ,cated and th tool driving means is journaled,

said controlling means being operably mounted upon the handle and adapted to engage or disengage the second gear from the first gear, and means interposed between the handle and the controlling means for automatically causing the latter to disengage the second gear from the first gear.

4. A driving mechanism comprising a handle, a tubular member secured in said handle and provided with a slot arranged between two side walls of the tubular member, a shaft journaled in said tubular member, means for driving said shaft, a worm gear fixed to the shaft and projecting into said slot, manually actuated means operably mounted upon the handle and provided with a slot adjacent to the first-mentioned slot and arranged between two side walls of the controlling means and which project between the two first mentioned side walls, a worm wheel located in the controlling means and projecting into the slot of the latter, said worm wheel being adapted to be engaged and disengaged from the worm gear by means of the controlling means, and a shaft journaled in and extending transversely through the manual controlling means and upon which the worm wheel is fixed, said shaft being adapted to drive a rotatable tool.

5. A driving mechanism comprising a handle, a shaft located in said handle, means for driving said shaft, a first gear fixed to said shaft, a second gear adapted to be driven by said first gear, a rotary member fixed to the second gear and adapted to drive a rotatable tool, manually actuated controlling means in which the second gear is located and the rotary member is journaled,

an element projecting from the handlev and upon which the controlling means is operably mounted, and an expansible member interposed between the handle and the controlling means to cause th latter to automatically disengage the second gear from the first gear.

6. A driving mechanism comprising a handle, a tubular member secured in said handle, a shaft journaled in said tubular member, a first gear fixed to said shaft, a second gear adapted to be driven by said first gear, a rotary member fixed to the second gear and adapted to drive a rotatable tool, manually actuated controlling means in which the rotary member is journaled, said controlling means being operably mounted upon the handle and adapted to engage or disengage the-second gearfrom the first gear, an electric motor, a flexible shaft adapted to be driven by said electric motor and be detachably connected to the shaft in the tubular member, a nonrotary flexible tube in which said flexible shaft is housed, and coupling means for detachably connecting said flexible tube to the tubular member in the handle.

SAMUEL M. COFFMAN. 

